JP5372527B2 - Ophthalmic laser treatment device - Google Patents

Description

  The present invention relates to an ophthalmic laser treatment apparatus that performs photocoagulation treatment by irradiating a patient's eye with laser light.

  A conventional laser treatment apparatus that performs photocoagulation treatment by irradiating the fundus with a laser beam is configured to irradiate an affected area of a patient's eye with a laser beam formed in one spot. When changing the spot position of the laser beam, the operator moves the delivery optical system that guides the laser beam, or moves the reflection mirror that reflects the laser beam toward the patient's eye by operating the manipulator. (For example, refer to Patent Document 1).

  In addition, an apparatus has been proposed in which an operator scans one spot of laser light with a scanner in a predetermined pattern instead of moving a reflecting mirror (see, for example, Patent Documents 2 and 3).

JP 2002-224154 A WO2007 / 035855 A2 Special table 2008-504075 gazette

  However, in the conventional device of Patent Document 1, when irradiating a large number of affected areas with laser light as in retinal photocoagulation, the operator must move the delivery optical system or reflection mirror for each laser light irradiation position. In addition, it took time and treatment time.

  In an apparatus using a scanner as in Patent Documents 2 and 3, although the labor of the operator is reduced, since one spot is moved, the laser irradiation time at each spot position is the same as that in Patent Document 1 When the time is set, the treatment time is long and the burden on the patient increases. If the laser irradiation time at each spot position is shortened and the output of the laser beam is increased instead, the experience of the previous operator will not be utilized, and appropriate coagulation spots will not be formed easily. There is a concern that the patient's eye pain and bleeding are likely to occur as the output increases.

  The present invention provides a technique for providing an ophthalmic laser treatment apparatus that can reduce the labor of an operator and shorten the treatment time and can perform treatment under irradiation conditions that make use of the experience of the operator. Let it be an issue.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) In an ophthalmic laser treatment apparatus that irradiates a patient's eye with laser light, the apparatus includes a delivery optical system that forms laser light emitted from a laser light source into a plurality of spots on a target surface of the patient's eye , and the delivery optical system includes: a diffractive optical element for splitting the laser beam incident to a plurality of diffraction light of a predetermined pattern, arranged in the laser light source side of the diffraction optical element, a first changing the spot size without changing the spot spacing in the target surface A zoom optical system; and a second zoom optical system that is disposed on the target surface side of the diffractive optical element and changes a spot interval and a spot size on the target surface .

  According to the present invention, it is possible to reduce the labor of the operator and shorten the treatment time, and it is possible to perform treatment under irradiation conditions that make use of the experience of the operator.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an ophthalmic laser treatment apparatus. FIG. 2 is a configuration diagram of the optical system and the control system.

  The laser treatment apparatus includes a slit lamp 1 provided with an observation optical system 10 and an illumination optical system 20 of a binocular microscope, an apparatus main body 50 in which a laser light source is disposed, and an optical fiber 30 that transmits laser light from the apparatus main body 50. And a laser delivery optical system 40 that irradiates the affected part such as the fundus of the patient's eye with the laser light emitted from the optical fiber 30. The observation optical system 10, the illumination optical system 20, and the laser delivery optical system 40 are mounted on the movable table 2 that can move on the base 3. The base 3 is provided with a chin rest 4 that supports the patient's face. The moving table 2 is moved with respect to the patient's eye by a joystick 5 operated by an operator.

  In FIG. 2, an observation optical system 10 includes an objective lens 11 shared by the left and right observation optical paths, a variable power lens unit 12 arranged in each of the left and right optical paths, an operator protection filter 13, an imaging lens 14, and an erecting prism. 15, a field stop 16, and an eyepiece 17.

  The visible light beam emitted from the illumination light source 21 of the illumination optical system 20 passes through the condenser lens 22, and then the height is determined by the variable aperture 23 and the width is determined by the variable slit plate 24, and is formed into a slit-shaped light beam. The slit illumination light that has passed through the variable slit plate 24 passes through the projection lens 25 and is then reflected by the mirror 26 to illuminate the patient's eye PE. In the case of fundus observation and fundus photocoagulation, a contact lens CL that cancels the refractive power of the cornea is used.

  The apparatus main body 50 includes a treatment laser light source 51 and an aiming light source 52 such as a semiconductor laser that generates red aiming light. The laser light source 51 emits laser light with a visible wavelength (for example, wavelength 532 nm) suitable for photocoagulation treatment. A part of the laser light emitted from the laser light source 51 is reflected by the beam splitter 53, and the output of the laser light is monitored by the output sensor 54. The laser light transmitted through the beam splitter 53 is made coaxial with the aiming light from the aiming light source 52 by the dichroic mirror 55, and is incident on the optical fiber 30 by the condenser lens 56.

  Laser light and aiming light emitted from the apparatus main body 50 are transmitted to the laser delivery optical system 40 through the fiber 30. In the embodiment of FIG. 2, a fiber 30 having a core diameter of 50 μm is used.

  The laser delivery optical system 40 includes a diffractive optical element (hereinafter abbreviated as DOE) 44 for forming a plurality of spots having a predetermined pattern on the target surface FO (fundus). The first zoom optical system 41 is disposed on the laser light source 51 side that is the incident side of the DOE 44 with the DOE 44 interposed therebetween, and the second zoom optical system 45 is disposed on the target surface FO side that is the emission side of the DOE 44. Yes. The laser light (and aiming light) that has passed through the second zoom optical system 45 is reflected by the dichroic mirror 48 disposed on the illumination optical axis of the illumination optical system 20 and is shared by the illumination optical system 20. It is directed to the patient's eye through the mirror 26. Note that the dichroic mirror 48 has characteristics of substantially reflecting the laser light from the laser light source 51, reflecting the red aiming light to some extent, and transmitting the white light from the illumination light source 21 to some extent.

  The first zoom optical system 41 includes a convex lens 42a and a concave lens 42b that are moved in the optical axis direction. The convex lens 42a serves as a variator lens, and the spot size formed on the target surface FO can be changed by the movement of the convex lens 42b. The concave lens 42b serves as a compensator lens, and is moved in the optical axis direction in conjunction with the convex lens 41a so that a substantially parallel light beam is incident on the DOE 44. The convex lens 42a and the concave lens 42b are moved in the optical axis direction in conjunction with a drive unit 43 having a motor and a moving mechanism. However, a well-known zoom lens barrel cam mechanism used for a photographic camera or the like is used. be able to. Further, by using the zoom lens barrel cam mechanism, the convex lens 42a and the concave lens 42b can be moved in conjunction with each other even by manual operation.

  The second zoom optical system 45 includes a convex lens 46a and a concave lens 46b that are moved in the optical axis direction. A parallel light beam is incident on the convex lens 46a through the first zoom optical system 41, and an enlarged image of the exit end face (core) of the fiber 30 serving as an object surface is formed on the focal plane of the convex lens 46a. In the configuration in which the DOE 44 is disposed between the first zoom optical system 41 and the second zoom optical system 45, a multi-spot is formed on the focal plane of the convex lens 46a according to the diffraction angle of the DOE 44. The concave lens 46b serves to expand a spot formed on the focal plane of the convex lens 46a by the DOE 44 and the convex lens 42a. The convex lens 46a is moved in conjunction with the concave lens 46b so that the target surface FO is in focus. In the second zoom optical system 45, the convex lens 46a functions as a compensator lens, and the concave lens 46b functions as a variator lens. The convex lens 46a and the concave lens 46b are moved in the direction of the optical axis in conjunction with a drive unit 47 having a motor and a moving mechanism. However, as with the first zoom optical system 41, a known zoom lens barrel cam mechanism is used. can do. The second zoom optical system 45 may be configured such that each component lens is manually moved instead of using the drive unit 47.

  The DOE 44 is an optical element in which minute grooves that generate diffraction are formed in a light transmitting body such as glass, quartz, or resin. By designing the minute groove of the DOE 44, it is possible to give a diffraction phenomenon of an arbitrary pattern to the light passing through the DOE 44. The DOE 44 of the present embodiment is designed to branch incident laser light into a plurality of diffracted lights of a predetermined pattern and form a plurality of spots (multi-spots) of a predetermined pattern on the target surface. For example, as shown in FIG. 5A, the branching of the diffracted light by the DOE 44 is designed so that nine circular spots are arranged in a lattice pattern at equal intervals on the focal plane of the convex lens 46a, and the core diameter is 50 μm. When the magnification changed by the first zoom optical system 41 and the second zoom optical system 45 is 1 ×, the spot on the target surface FO has a diameter of 50 μm, and the distance between the centers of the spots is 100 μm. It is designed to be. Further, the DOE 44 is designed so that the size and energy intensity of each spot of the multi-spot are all substantially the same. In addition, in DOE, the shape of one spot can be freely designed such as a square shape, a hexagonal shape, etc. in addition to a circular shape.

  Connected to the control unit 60 disposed in the apparatus main body 50 are a laser light source 51, an aiming light source 52, an output sensor 54, drive units 43 and 47, a foot switch 8 for inputting a laser irradiation trigger signal, a controller 61, and the like. ing. The controller 60 controls the output of the laser beam, the duration, and the on / off switching of the aiming beam. The controller 61 has a switch 61a for changing the spot size of the laser beam, a switch 61b for setting the irradiation range of the laser beam (the overall size of the multi-spot), an output (energy amount) of the laser beam, Various switches such as a switch for setting a surgical parameter such as an irradiation time and a switch for adjusting the amount of illumination light are provided. Further, the controller 61 is provided with a display (display device) 64 for displaying surgical conditions set by various switches. The control unit 60 controls driving of the drive units 43 and 47 for changing the laser light emission conditions, the spot size, and the like of the laser light source 51 based on the parameter setting by the controller 61.

  Next, the principle of changing the size and irradiation range of the spot irradiated on the target surface will be described. FIG. 3 is a configuration diagram of main optical members of the laser delivery optical system 40. In FIG. 3, the magnification that can be changed by the first zoom optical system 41 (ie, the magnification that can be changed by moving the convex lens 42a) is β1, and the magnification that can be changed by the second zoom optical system 45 (ie, the concave lens 46b can be moved). Β4, the focal length of the concave lens 42b is f2, and the focal length of the convex lens 46a is f3. Here, when the magnification β4 = 1 by the second zoom optical system 45 is set, the following relationship exists between the magnification M of the spot size formed on the target surface FO and the magnification by the first zoom optical system 41 to β1. is there. In the following equation, C is a magnification (constant) determined by the projection lens 25.

Due to the diffracted light branched by the DOE 44, for example, as shown in FIG. 5A, nine spots S having the same size and the same shape are formed on the target surface. At this time, since the focal length f2 of the concave lens 42b and the focal length f3 of the convex lens 46a are fixed, the magnification M of each spot S is determined by the magnification β1 of the first zoom optical system 41. When the magnification β4 by the second zoom optical system 45 is changed, the magnification M of each spot S is calculated by the following equation.
That is, when the magnification β4 by the second zoom optical system 45 is changed, the magnification M of the spot S is determined by both the magnification β1 by the first zoom optical system 41 and the magnification β4 by the second zoom optical system 45. The For example, when only the entire irradiation range is changed without changing the spot size, the magnification by the first zoom optical system 41 according to the magnification β4 by the second zoom optical system 45 so that the spot magnification M is constant. β1 will be regulated.

As shown in FIG. 4, the convex lens 46a forms an enlarged image of the emission end face 31a of the fiber 30 as a light source image on the focal plane A of the convex lens 46a. When the DOE 44 is disposed between the concave lens 42b and the convex lens 46a, a plurality of spots are formed on the focal plane A of the convex lens 46a according to the diffraction angle of the DOE 44. When a certain diffraction angle of the DOE 44 is θ, the distance d from the optical axis L1 of one spot formed on the focal plane A by the diffraction angle θ is
Is represented as By designing the DOE 44 so as to have a plurality of diffraction angles θ, a plurality of spots corresponding to the diffraction angles θ are formed on the focal plane A.

The convex lens 46a of the second zoom optical system 45 serves to expand the multi-spot formed on the focal plane A of the convex lens 46a. The convex lens 46a is moved in conjunction with the concave lens 46b so that the target surface FO is in focus. When the spot interval formed on the focal plane A of the convex lens 46 a is d, the following relationship is established between the spot interval D on the target surface FO and the magnification β4 by the second zoom optical system 45.
That is, the spot interval D is determined by the magnification β4 by the second zoom optical system 45.

  FIG. 5 is an explanatory diagram in the case of changing only the spot interval D without changing the spot size φ on the target surface FO. FIG. 5A shows nine multi-spots formed on the target surface FO. For example, when the magnification β1 = 1 and the magnification β4 = 1, the spot size φ is φ1 = 50 μm, and the equally spaced spot intervals D are D1 = 100 μm.

  FIG. 5B shows a case where the spot size φ1 remains 50 μm and the spot interval D is set to D2 = 200 μm, which is twice that of FIG. In this case, by increasing (doubled) the magnification β4 of the second zoom optical system 45, the spot interval D is also expanded (doubled) with respect to FIG. However, when the magnification β4 is increased, the size φ of each spot S is also enlarged. Therefore, the magnification β1 by the first zoom optical system 41 is adjusted so that the magnification M of the spot size φ is constant. That is, in this example, the magnification β4 = 2 is set and the magnification β1 = 0.5 is adjusted.

  FIG. 5C shows the case where the spot size φ1 remains 50 μm and the spot interval D is set to D3 = 300 μm, which is twice that of FIG. In this case, the magnification β4 = 3 is set and the magnification β1 = 1/3 is adjusted.

  As in these examples, when only the spot interval D is changed while the spot size φ is kept constant, the magnification β4 by the second zoom optical system 45 is changed according to the enlargement (reduction) of the spot interval D. At the same time, the magnification β1 by the first zoom optical system 41 is also changed according to the magnification β4 so that the magnification M of the spot size φ is constant.

  FIG. 6 is an explanatory diagram when the spot size φ is changed without changing the spot interval D formed on the target surface FO. FIG. 6A shows a case where the spot size φ is φ1 = 50 μm and the spot interval D is D3 = 300 μm, as in FIG. 5C. In this case, the magnification β1 = 1/3 and the magnification β4 = 3.

  FIG. 6B shows a case in which the spot size φ is changed to φ2 = 100 μm while the spot interval D remains D3 = 300 μm with respect to FIG. In this case, the magnification β1 by the first zoom optical system 41 is set to β1 = 2/3 so that the spot size φ1 in FIG. 6A is doubled, and the magnification β4 by the second zoom optical system 45 is As in 6 (a), β4 = 3 is maintained. FIG. 6C shows a case in which the spot size φ is changed to φ3 = 200 μm while the spot interval D remains D3 = 300 μm, compared to FIG. In this case, the magnification β1 by the first zoom optical system 41 is set to β1 = 4/3 so that the spot size φ1 in FIG. 6A is four times, and the magnification β4 by the second zoom optical system 45 is As in FIG. 6A, β4 = 3 is maintained.

  As in these examples, when only the spot size φ is changed while the spot interval D is fixed, only the magnification β1 is changed without changing the magnification β4. Further, when the spot size φ is displayed on the display (display) 64, the spot size φ is calculated by the control unit 60 based on the magnification β1 and the magnification β4.

  Next, the operation | movement at the time of the surgery of a laser treatment apparatus is demonstrated. Here, the case where the photocoagulation treatment of the fundus is performed will be described. During the photocoagulation treatment, the operator determines the irradiation time, output, and the like of the laser light with various switches (not shown) of the controller 61. The irradiation time and output are also displayed on the display 64. The laser output displayed on the display 64 is displayed as an output per spot so as to display the entire laser output value and to make use of the operator's experience. For example, when the laser output of one spot is set to 0.1 W, the control unit 60 sets the overall laser output to 0.9 W based on the number of diffracted lights (number of spots) branched by the DOE 44. In addition, the laser light source 51 is driven.

  In addition, the operator sets the spot size φ by the switch 61a for changing the spot size, and the spot interval D by the switch 61b (this may be a range of nine spots S that is the irradiation range of the laser light). Set. The spot size φ and the spot interval D are displayed on the display 64. When the spot interval D is set, the control unit 60 determines the magnification β4 based on the setting signal of the spot interval D and controls the drive unit 47 to drive the second zoom optical system 45. Further, the control unit 60 determines the magnification β1 by the first zoom optical system 41 based on the driving information (magnification β4) of the second zoom optical system 45 and the setting signal of the spot size φ, and sets the spot size φ of the set value. The drive unit 43 is controlled so that the first zoom optical system 41 is driven. For example, in the above-described conditions of FIGS. 5 and 6, when the spot interval D is 300 μm, the magnification β4 = 3 by the second zoom optical system 45 is set, and when the spot size φ is set to 200 μm, The magnification β1 = 4/3 by the one zoom optical system 41 is determined.

  The surgeon observes the affected part of the fundus illuminated by the illumination light from the illumination optical system 20 with the observation optical system 10. When the aiming light source 52 is turned on, the aiming light from the aiming light source 52 is guided to the laser delivery optical system 40 through the fiber 30, and the first zoom optical system 41, the DOE 44, the second zoom optical system 45, and the projection lens 25 are passed through. By passing, nine multi-spots as shown in FIG. 5 are formed. Since the aiming light is coaxial with the laser light, the fundus is irradiated so as to have the spot size and the spot interval set by the controller 61. The surgeon observes nine multi-spots of aiming light irradiated on the fundus and operates the joystick 5 and the like to move the slit lamp 1 and the laser delivery optical system 40 so as to aim the affected part. When changing the nine spot intervals D by observing multi-spots of aiming light irradiated to the affected area, the operator operates the switch 61b. The controller 60 determines the magnification β4 by the second zoom optical system 45 according to the change of the spot interval D, moves the convex lens 46a and the concave lens 46b, and maintains the set value of the spot size φ so as to maintain the set value of the spot size φ. Accordingly, the magnification β1 by the first zoom optical system 41 is determined, and the convex lens 42a and the concave lens 42b are moved.

  Nine spots formed by the aiming light are observed, and when the aiming on the affected area is completed, the foot switch 8 is used to perform laser irradiation. When a laser irradiation trigger signal is input from the foot switch 8, the control unit 60 drives the laser light source 51 to emit laser light. The laser light from the laser light source 51 is guided to the delivery optical system 40 by the optical fiber 30 and passes through the first zoom optical system 41, the DOE 44, the second zoom optical system 45, and the projection lens 25, and is divided into nine spots. Is irradiated onto the fundus at a time for the set irradiation time. As a result, nine coagulation spots are formed simultaneously. In the treatment of forming many coagulation spots such as retinal photocoagulation, the laser beam of 9 spots is irradiated onto the fundus at a time, reducing the operator's alignment effort and shortening the treatment time. Can be planned. In addition, since it is possible to perform treatment under the same irradiation time and laser output conditions as when performing laser irradiation for each spot, it is possible to perform appropriate treatment utilizing the experience of the operator.

  In the above embodiment, an example in which the DOE 44 that forms a pattern in which nine spots are arranged in a grid pattern has been described. However, a plurality of DOEs that differ in the formation of a multi-spot arrangement pattern are prepared. If the irradiation pattern can be selected, more appropriate treatment can be performed according to the state of the affected area.

  FIG. 7 is a configuration example that enables selection of an array pattern of multi-spots. On the same circumference of the turret plate 100, DOEs 101a, 101b, 101c, 101d, 101e and openings 102 for forming different multi-spot patterns are arranged. Instead of the DOE 44 in FIG. 2, the turret plate 100 is rotated by a rotating unit 103 configured by a motor or the like, so that one of the DOEs 101 a to 101 e and the opening 102 is the first zoom optical system of the laser delivery optical system 40. 41 and the second zoom optical system 45. The rotation unit 103 is driven by the control unit 60 based on a signal of a selection switch provided in the controller 61. A configuration in which the DOEs 101a, 101b, 101c, 101d, and 101e having a desired pattern can be switched by manually rotating the turret plate 100 by the surgeon is also possible.

  The DOEs 101a to 101e are rotatably held by the turret plate 100 by the holders 104a to 104e. The holders 104a to 104e are rotated in conjunction with each other when the sun gear 105 is rotated by the motor 106. When the DOEs 101a to 101e arranged on the optical axis of the laser delivery optical system 40 are rotated around the optical axis, the pattern of the multi-spot irradiated to the patient's eye is also rotated. The motor 106 is driven by the control unit 60 based on a signal from a switch for designating a rotation angle provided in the controller 61. As for the rotation of each of the DOEs 101a to 101e around the optical axis, a multi-spot pattern can be rotated by manually rotating the DOE or the sun gear 105 by the operator.

  FIG. 8 is an example of a multi-spot pattern formed by the DOEs 101a to 101e. FIG. 8A shows a pattern in which multi-spots are arranged in a lattice pattern, FIG. 8B shows a pattern in which multi-spots are arranged in an annular shape, and FIG. 8C shows a multi-spot in a triangular shape. FIG. 8D shows a pattern in which multi-spots are arranged in a fan shape, and FIG. 8E shows a pattern in which multi-spots are arranged in a line. The annular pattern in FIG. 8B is convenient when, for example, avoiding macula on the fundus and photocoagulating the entire area around the macula. The fan-shaped pattern in FIG. 8 (d) is convenient when partially photocoagulating around the macula. By rotating the DOE 101d around the optical axis, the fan-shaped pattern is also rotated in an arbitrary direction. The Also in the triangular pattern in FIG. 8C and the line pattern in FIG. 8E, the multi-spot array pattern is rotated by rotating the respective DOEs 101c and 101e around the optical axis. When the aperture 102 is placed in the optical path (that is, when the DOE escapes from the optical path), the laser light from the laser delivery optical system 40 is formed in a single spot, and treatment with a single spot is possible as in the conventional apparatus. To be. In the configuration having the DOE 44 in FIG. 2 described above, it is also possible to select a single spot by enabling the DOE 44 to be selectively inserted into and removed from the optical path by the moving mechanism.

  In the above method, the first zoom optical system 41 and the second zoom optical system 45 are electrically driven when changing the spot diameter and the irradiation range. However, when the operator operates the rotary knob or the like, The first zoom optical system 41 and the second zoom optical system 45 may be manually moved. In this case, the first zoom optical system 41 and the second zoom optical system 41 and the second zoom optical system 45 are provided with a sensor for detecting the movement position of each lens or the operation position of the rotary knob. The zoom optical system 45 may be configured to detect magnifications, and information on the spot size φ and the spot interval D (or irradiation range) may be displayed on the display 64 based on the detection of the magnifications. Thus, the surgeon can perform appropriate laser irradiation while confirming the spot size φ and the spot interval D.

  In the embodiment of FIG. 2, the laser light from the laser light source 51 is guided to the laser delivery optical system 40 through the fiber 30, but the laser light from the laser light source 51 is not passed through the fiber 30. A guided configuration may be used. In this case, the focal plane relayed by the laser light source 51 or a lens or the like is used as the object plane of the first zoom optical system 41 instead of the emission end face of the fiber 30.

It is a schematic block diagram of the ophthalmic laser treatment apparatus. It is a block diagram of an optical system and a control system. It is a block diagram of the main optical members which a laser delivery optical system has. It is explanatory drawing about the distance from the optical axis of the spot formed in a focal plane. It is explanatory drawing in the case of changing only a spot space | interval, without changing spot size. It is explanatory drawing in the case of changing a spot size, without changing a spot space | interval. It is a structural example which enables selection of the multi-spot arrangement pattern. It is an example of the pattern of a multi spot.

DESCRIPTION OF SYMBOLS 10 Observation optical system 20 Illumination optical system 40 Laser delivery optical system 41 1st zoom optical system 44 Diffractive optical element 45 2nd zoom optical system 51 Laser light source 60 Control part 61 Controller 61a, 61b Switch 64 Display 100 Turret board

Claims (1)

In an ophthalmic laser treatment apparatus that irradiates a patient's eye with laser light,
A delivery optical system for forming laser light emitted from a laser light source into a plurality of spots on a target surface of a patient's eye ;
The delivery optical system is:
A diffractive optical element that branches incident laser light into a plurality of diffracted lights of a predetermined pattern;
Disposed on the laser light source side of the diffraction optical element, a first zoom optical system to change the spot size without changing the spot spacing in the target surface,
A second zoom optical system that is disposed on the target surface side of the diffractive optical element and changes a spot interval and a spot size on the target surface;
An ophthalmic laser treatment apparatus comprising: